From 36a2138cce66a164f08a36c4c5820b133c4590fd Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Thu, 1 Mar 2012 02:16:57 +0000
Subject: [PATCH] Emit the "is an intrinsic overloaded" table as a bitfield.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151792 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp | 11 ++++-------
 lib/VMCore/Function.cpp                   |  4 ----
 utils/TableGen/IntrinsicEmitter.cpp       | 17 ++++++++++-------
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp b/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
index b3651158a37..91aaf940e62 100644
--- a/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
+++ b/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
@@ -74,16 +74,13 @@ lookupGCCName(const char *Name) const {
 }
 
 bool MBlazeIntrinsicInfo::isOverloaded(unsigned IntrID) const {
-  // Overload Table
-  const bool OTable[] = {
+  if (IntrID == 0)
+    return false;
+
+  unsigned id = IntrID - Intrinsic::num_intrinsics + 1;
 #define GET_INTRINSIC_OVERLOAD_TABLE
 #include "MBlazeGenIntrinsics.inc"
 #undef GET_INTRINSIC_OVERLOAD_TABLE
-  };
-  if (IntrID == 0)
-    return false;
-  else
-    return OTable[IntrID - Intrinsic::num_intrinsics];
 }
 
 /// This defines the "getAttributes(ID id)" method.
diff --git a/lib/VMCore/Function.cpp b/lib/VMCore/Function.cpp
index 8238f632152..af6344ef616 100644
--- a/lib/VMCore/Function.cpp
+++ b/lib/VMCore/Function.cpp
@@ -372,13 +372,9 @@ FunctionType *Intrinsic::getType(LLVMContext &Context,
 }
 
 bool Intrinsic::isOverloaded(ID id) {
-  static const bool OTable[] = {
-    false,
 #define GET_INTRINSIC_OVERLOAD_TABLE
 #include "llvm/Intrinsics.gen"
 #undef GET_INTRINSIC_OVERLOAD_TABLE
-  };
-  return OTable[id];
 }
 
 /// This defines the "Intrinsic::getAttributes(ID id)" method.
diff --git a/utils/TableGen/IntrinsicEmitter.cpp b/utils/TableGen/IntrinsicEmitter.cpp
index c5e36239a53..578b3aa2439 100644
--- a/utils/TableGen/IntrinsicEmitter.cpp
+++ b/utils/TableGen/IntrinsicEmitter.cpp
@@ -160,17 +160,20 @@ EmitIntrinsicToNameTable(const std::vector<CodeGenIntrinsic> &Ints,
 void IntrinsicEmitter::
 EmitIntrinsicToOverloadTable(const std::vector<CodeGenIntrinsic> &Ints, 
                          raw_ostream &OS) {
-  OS << "// Intrinsic ID to overload table\n";
+  OS << "// Intrinsic ID to overload bitset\n";
   OS << "#ifdef GET_INTRINSIC_OVERLOAD_TABLE\n";
-  OS << "  // Note that entry #0 is the invalid intrinsic!\n";
+  OS << "static const uint8_t OTable[] = {\n";
+  OS << "  0";
   for (unsigned i = 0, e = Ints.size(); i != e; ++i) {
-    OS << "  ";
+    // Add one to the index so we emit a null bit for the invalid #0 intrinsic.
+    if ((i+1)%8 == 0)
+      OS << ",\n  0";
     if (Ints[i].isOverloaded)
-      OS << "true";
-    else
-      OS << "false";
-    OS << ",\n";
+      OS << " | (1<<" << (i+1)%8 << ')';
   }
+  OS << "\n};\n\n";
+  // OTable contains a true bit at the position if the intrinsic is overloaded.
+  OS << "return (OTable[id/8] & (1 << (id%8))) != 0;\n";
   OS << "#endif\n\n";
 }